The present invention relates to a controlling device having a plurality of controllers which perform control so that the controlled variables of a plurality of control loops agree with their preset values and, more particularly, to a controlling device and controlling method capable of realizing energy saving by reducing the settling standby times of controllers except the slowest control loop where the variation of the controlled variable is the slowest.
Apparatuses (e.g., a semiconductor manufacturing apparatus using an electric heater as an actuator) in which one device incorporates a plurality of loops of a control system have conventionally been known. In this apparatus, the controllers of the respective control loops are independently operated.
The controlled variables of the control loops do not always vary at the same speed. With a speed difference between variations in the controlled variables of the control loops, the responses of control loops except the slowest control loop exhibiting the slowest variation become faster than the response of the slowest control loop. While maintaining the settling state, the controllers of the control loops except the slowest control loop must wait until the response of the slowest control loop is completed. These controllers require a settling standby time during which the controllers stand by while maintaining the settling state upon the completion of the response. The controllers suffer an increase in energy consumption by the settling standby time.
The present invention has been made to overcome the conventional drawbacks, and has as its object to provide a controlling device and controlling method capable of realizing energy saving by reducing the settling standby times of controllers except the slowest control loop.
According to the present invention, there is provided a controlling device comprising a first controller (PID1) which performs control so as to make a controlled variable of a first control loop agree with a preset value, at least one remaining controller (PID2-PIDn) which performs control so as to make a controlled variable of at least one remaining control loop where variation of the controlled variable is higher than in the first control loop agree with a preset value, a step response progress calculating section (C_R1) which calculates a step response progress (xcex11) of the first control loop, and a control loop internal preset value calculating section (C_S2-C_Sn) which is arranged for each remaining controller, corrects the preset value of a corresponding remaining control loop on the basis of the step response progress so as to make the controlled variable of the corresponding remaining control loop vary synchronously with the controlled variable of the first control loop, and gives the corrected preset value to the remaining controller.
According to the present invention, there is provided a controlling device comprising a plurality of controllers (PID1-PIDn) which perform control so as to make controlled variables of a plurality of control loops agree with preset values, a plurality of step response progress calculating sections (C_R1a-C_Rna) which are arranged for the respective controllers and calculate step response progresses (xcex11-xcex1n) of the corresponding control loops, a slowest step response progress calculating section (C_Rm) which selects the slowest progress (xcex1min) among the step response progresses calculated by the step response progress calculating sections, and control loop internal preset value calculating sections (C_S1a-C_Sna) which are arranged for the respective controllers, correct the preset values of the corresponding control loops on the basis of the slowest progress so as to make the controlled variables of the corresponding control loops vary synchronously with the slowest-progress controlled variable, and give the corrected preset values to the corresponding controllers.
According to the present invention, there is provided a controlling method in a controlling device having a plurality of controllers which perform control so as to make controlled variables of a plurality of control loops agree with preset values, comprising the steps of calculating a step response progress of a first control loop where variation of the controlled variable is the slowest, and correcting the preset values of the remaining control loops on the basis of the step response progress so as to make the controlled variables of the remaining control loops except the first control loop vary synchronously with the controlled variable of the first control loop, thereby giving the corrected preset values to the corresponding controllers.
According to the present invention, there is provided a controlling method comprising the steps of calculating step response progresses of the control loops, selecting the slowest progress among the calculated step response progresses, and correcting the preset values of the control loops on the basis of the slowest progress so as to make the controlled variables of the control loops vary synchronously with the slowest-progress controlled variable, thereby giving the corrected preset values to the controllers.